The subject invention relates to leveling machines of the type that are usually used for leveling sheet or strip steel or aluminum wherein the sheets or strips are wound into a coil that needs to be flattened before being used in further manufacturing processes. Such leveling machines typically include pluralities of upper and lower leveler rolls, relatively offset, to effectively flex the strip back and forth until the coil tendencies are worked out and the strip is flat. The leveling rollers actually engaging the workpiece are supported over their length by full length backup rolls which in turn are supported by cam follower backup rolls, all effectively supported by a frame housing.
Leveling machines for working the coiling tendencies out of wound strip or sheet are well known. Such leveling assemblies typically comprise a frame supporting a cassette portion having the work rolls and disposed within the frame. The machine is configured to receive the workpiece at a work area defined by opposed and offset work rolls. The line of work rolls are positioned to effectively work the strip back and forth until the coiling tendencies are removed from the workpiece, and the piece is flat and more useful for further manufacturing processes.
It is common to support the work rolls with adjacent and engaging full length backup rolls which buttress the work rolls into the desired positions relative to the workpiece. The backup rolls are essentially coextensive with the work rolls to provide corresponding full length backup. The full length backup rolls are in turn supported by a plurality of cam follower backup rolls which are usually somehow mounted to the frame by braces, but are configured to engage only a portion of the full length backup rolls. In other words, the cam follower backup rolls are not dimensioned to extend across and engage the full length of the backup rolls. The relative dimensioning of the cam follower backup rolls to engage only a portion of the full length backup rolls better accommodates the cassette portion construction and its reception in the frame housing.
The particular problems which are overcome by the subject invention result from the wear engagement between the cam follower backup rolls and the full length backup rolls. More particularly, since the cam follower backup rolls contact only a portion of the full length backup rolls, the engaging portions remain static and therefore constant, and wear areas, typically comprising depressions in the backup rolls, can occur. Changes in the relative dimensioning of the cam follower backups and the full length backups between the frame and workpiece will necessarily affect the dimensioning and relative positioning of the work rolls relative to the frame and the workpiece, and thereby have undesirable effects on the efficiency of the overall leveling process, as well as on the useful life of the components in the leveling assembly. When such problems arise to the level that repair or reconstruction of the leveling assembly is needed, entire sets of full length backup rolls have to be removed and replaced, requiring extensive repair work, substantial disassembly of the overall apparatus, and the discarding of the unacceptably worn full length backup rolls, not to mention the problems of the down time of the leveling machine itself. A related inefficiency is that the wear areas on the full length backup rolls are limited to only certain portions comprising the engagement areas. Other areas of the full length backups are not worn at all.
There is a substantial need to provide a leveling assembly which either avoids or compensates for such wear problems, and which can do so in a manner that is reliable, consistent and convenient to an operator.
The subject invention contemplates a new and improved leveling assembly which overcomes the above problems and others to provide a new leveler which avoids assembly failure due to wear on the full length backup rolls, is readily adaptable to a plurality of leveling assemblies having a variety of dimensioning characteristics, reduces the need for repair and reconstruction of the assembly, and which provides improved longevity and accuracy in operation of leveling apparatus.
In accordance with the present invention, there is provided an assembly for leveling a metal workpiece during movement of the piece therethrough, including a work roll for engaging and working the strip. A backup roll supports the work roll against the strip. A cam roll supports the backup roll against the work roll. A frame supports the cam roll against the backup roll. A positioning guide is associated with the backup roll for selectively adjusting a relative position of the backup roll to the cam followers for compensating for wear on the backup roll caused by the cam followers. The adjusting of the relative position comprises moving the area of engagement between the cam roll and the backup roll.
In accordance with another aspect of the invention, the position guide is supported by the frame and is disposed for adjusting the relative position of the backup rolls in a direction transverse to the strip movement. The position guide includes an adjustment member connected to an end portion of the backup roll at a first adjuster end, and the frame at the second adjuster end, whereby operator control of the position guide adjuster correspondingly adjusts the spacing between the backup roll end portion and the frame. The result of such adjusting is a relative change in engagement position between the cam roll and the backup roll, thereby avoiding the prospects of undesired wear at a single position of engagement. A yoke assembly conveniently serves to facilitate the position adjustment of the plurality of backup rolls consistently and accurately.
In accordance with a more particular aspect of the invention, the backup roll is dimensioned to extend about a width of a strip workpiece. The cam roll comprises a plurality of cam rolls, each dimensioned to engage a portion of the backup roll and disposed to provide spacings between the areas of contact with the backup roll. The adjusting of the relative positions by the position guide assembly comprises adjusting the engaging portions for movement into at least a portion of the spacings.
In accordance with the present invention, a method is provided for flattening strip by adjusting a leveling apparatus to avoid or compensate for back up roll marks on component elements due to operating wear. The apparatus includes work rolls braced by a frame and intermediate rolls, wherein the frame engages the intermediate rolls at spaced positions. The method comprises steps of supporting the intermediate rolls to the frame with an adjustable guide system for adjusting a position of the intermediate rolls relative to the frame. In anticipation of undesired component wear, the guide systems are adjusted to shift the spaced positions of engagement between the frame and the intermediate rolls to different positions of engagement.
One benefit obtained by use of the present invention, is a leveling apparatus having a cassette portion comprising work rolls for flattening strip or sheet which minimizes wear problems on backup rolls supporting the work rolls.
A further benefit of the present invention is a yoke system for commonly supporting the backup rolls for facilitating accurate position adjustment of a plurality of backup rolls relative to the cam followers. The yoke is conveniently adjusted with an adjustment screw and guide pin assembly.
A further benefit of the present invention is the minimization of repair and reconstruction of the leveling apparatus due to dimensioning changes attributable to backup roll wear.
Other benefits and advantages for the subject invention will become apparent to those skilled in the art upon a reading and understanding of the specification.